1. Field of the Invention
The present invention relates to a backup system, backup device, backup request device, backup method, backup request method, backup program and backup request program, and is preferably applied to a backup system that makes the backup of music data or content data, for example.
2. Description of the Related Art
Typically, a backup system is designed to save in a hard disk drive music data the personal computer read out from a Compact Disc or purchased from a server on a network. The backup system is also designed to upload to a server a list of music identifications related to all pieces of music data the personal computer has stored in the hard disk drive.
When the personal computer cannot play back music data due to failure of the hard disk or the like, the backup system delivers, following the list of music identifications, music data to the personal computer for example after the hard disk drive is fixed and the personal computer requests to be restored. In this manner, the backup system allows the personal computer to store music data in the fixed hard disk drive again and to play back them (see Jpn. Pat. Laid-open Publication No. 2001-195509 [Page 21], for example).